JP2014059563A - Device for controlling operation of organic light-emitting diode display - Google Patents

Abstract

An apparatus for controlling the operation of an organic light emitting diode display is provided.
A system on chip (SoC) capable of controlling the operation of an organic light emitting diode (OLED) display includes a first conversion circuit that converts a first RGB value into a luminance value and a saturation value, and a first control. An adjustment circuit that adjusts the luminance value and the saturation value based on the value, a second RGB value is generated based on the adjusted luminance value and the adjusted saturation value, and the generated second RGB value is A second conversion circuit for outputting to the OLED display.
[Selection] Figure 1

Description

  Embodiments of the present invention relate to image data processing technology, and in particular, control the operation of an organic light emitting diode display capable of reducing power consumption while maintaining visual perceived brightness. It relates to a device that can do.

Due to the Helmholtz-Kohlrausch effect, the brightness depends on the luminance and chroma, and when the luminance is constant, the brightness increases as the saturation increases. To do.
The color model used in many digital video systems is the YCbCr (YUV) color model. The YCbCr (YUV) color space displays colors using three ordered elements. Y represents a luminance element, Cb represents a blue-difference chroma component, and Cr represents a red-difference chroma component. In YUV, UV represents two chrominance components.

YUV and Y′UV are used for analog encoding of color information in the TV system, and YCbCr is used for encoding color information suitable for video and still images. At this time, Y ′ represents a luma.
The color image is processed by a computer, and the processed color image is displayed via a display. As the brightness of each of the pixels included in the display increases, the power consumption in the display increases. Also, as the resolution of the display increases, the power consumption on the display also increases. That is, as the display resolution increases and the brightness of each pixel included in the display increases, the power consumption of the display further increases.

US Patent Application Publication No. 2011/0205202 US Patent Application Publication No. 2008/0032754 US Patent Application Publication No. 2010/0171751 US Patent Application Publication No. 2010/0164937 US Patent Application Publication No. 2010/0026724 JP 2004-012600 A JP 2011-101296 A Korean Patent Application Publication No. 2010/0078699 Specification

  The technical problem to be solved by the present invention is to reduce the power consumption in the organic light emitting diode display, while maintaining or increasing the visual cognitive brightness for the image displayed on the organic light emitting diode display. An object of the present invention is to provide an apparatus that can be made to operate.

  A system on chip (System On Chip: SoC) capable of controlling the operation of an organic light emitting diode (OLED) display according to an exemplary embodiment of the present invention uses a first RGB value as a luminance value and a saturation value. A first conversion circuit that converts the luminance value and the saturation value based on the first control value; a second RGB value based on the adjusted luminance value and the adjusted saturation value; And a second conversion circuit for outputting the generated second RGB values to the OLED display.

  A mobile application processor capable of controlling the operation of an organic light emitting diode (OLED) display according to an embodiment of the present invention includes a first conversion circuit that converts a first RGB value into a luminance value and a saturation value, and a first control value. And adjusting the luminance value and the saturation value, generating a second RGB value based on the adjusted luminance value and the adjusted saturation value, and generating the generated second RGB value as an OLED. A second conversion circuit that outputs to the display; a compensation circuit that adjusts at least one of the original RGB values based on the second control value to generate a first RGB value; and a display that outputs the original RGB value And a controller.

  A portable electronic device according to an embodiment of the present invention includes an organic light emitting diode (OLED) display, a first conversion circuit that converts a first RGB value into a luminance value and a saturation value, and a luminance based on the first control value. A second RGB value is generated based on the adjusted luminance value and the adjusted saturation value, and the generated second RGB value is output to the OLED display. A conversion circuit, a compensation circuit that adjusts at least one of the original RGB values based on the second control value to generate the first RGB value, and a display controller that outputs the original RGB value. .

The portable electronic device analyzes a histogram pattern defined as a cumulative distribution of each of the original RGB values, outputs a result of the analysis, a first control value based on the result of the analysis, And a control value generation circuit for generating a second control value.
The adjustment circuit includes a luminance control circuit that decreases the luminance value based on the luminance control value of the first control value, and a saturation that increases the saturation value based on the saturation control value of the first control value. A degree control circuit.

An apparatus for processing image data displayed on an organic light emitting diode display according to an embodiment of the present invention can increase a saturation value while reducing a luminance value that affects brightness.
The device not only reduces the power consumption in the organic light emitting diode display due to the reduced brightness value, but also increases the visual cognitive brightness of the image displayed in the organic light emitting diode display due to the increased saturation value. It can be kept or increased as compared to the visual cognitive brightness before adjusting the value and the saturation value.

1 is a block diagram of an image data display system according to an embodiment of the present invention. FIG. 4 is a block diagram of an image data display system according to another embodiment of the present invention. The histogram pattern figure of the image data input into the statistical analysis circuit of FIG. The histogram pattern figure of the image data input into the statistical analysis circuit of FIG. The histogram pattern figure of the image data input into the statistical analysis circuit of FIG. The histogram pattern figure of the image data input into the statistical analysis circuit of FIG. FIG. 3 is a pattern diagram for explaining the operation of the compensation circuit in FIG. 2. FIG. 3 is a pattern diagram for explaining the operation of the compensation circuit in FIG. 2. FIG. 3 is a pattern diagram for explaining the operation of the compensation circuit in FIG. 2. FIG. 3 is a pattern diagram for explaining the operation of the compensation circuit in FIG. 2. The conceptual diagram explaining the method to adjust a luminance value and a saturation value for every area | region. 5 is a flowchart illustrating an image data processing method according to an embodiment of the present invention.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.
FIG. 1 shows a block diagram of an image data display system according to an embodiment of the present invention. Referring to FIG. 1, an image data display system or image data processing system 100A includes a processor 200A, a display 300, and an external memory 400.

  The image data display system 100A includes a portable electronic device (portable electronic device) such as a smartphone, a tablet personal computer (PC), a laptop computer, a portable multimedia player (PMP), and an e-book reader (e-book reader). reader), mobile computer, PDA (Personal Digital Assistant), game controller, mobile Internet device, or PNA (Personal Navigation Assistant).

The processor 200A converts image data displayed on the display 300, for example, an original RGB value or a first RGB value related to the original RGB value into a luminance value and a saturation value, and based on at least one control value The brightness value is decreased, the saturation value is increased, a second RGB value is generated using the decreased brightness value and the increased saturation value, and the generated second RGB value is output to the display 300.
The processor 200A may be embodied as an application processor or a mobile application processor.

The display 300 displays image data with the second RGB values. The display 300 may be an OLED (Organic Light-Emitting Diode) display, an AMOLED (Active-Matrix Organic Light-Emitting Diode) display, an OLED-based flexible display, or an AMOLED-based flexible display.
The processor 200A may include a CPU 210, a display controller 215, a user interface 220, and an image data processing circuit 230A.

  The processor 200 </ b> A may further include a RAM (Random Access Memory) 212 and a ROM (Read Only Memory) 214. In addition, the processor 200A may process an access operation to the external memory 400, for example, an external memory controller 216 that can control a read operation or a write operation, and image data output from the external memory controller 216. A GPU (Graphics Processing Unit) 218 that can be further included. At this time, each of the components 210, 212, 214, 215, 216, 218, 220, and 230A can communicate with each other via at least one bus (not shown).

The CPU 210 can generally control the operation of the processor 200A. For example, the CPU 210 can control the operation of at least one of the RAM 212, ROM 214, display controller 215, external memory controller 216, GPU 218, user interface 220, and image data processing circuit 230A.
The display controller 215 may transmit original image data, eg, original RGB values, to the image data processing circuit 230A. The GPU 218 processes the image data input via the external memory controller 216 and transmits the processed image data to the display controller 215.

  A user or a manufacturer's test engineer can input various control values or user input values necessary for the operation of the processor 200 </ b> A via the user interface 220. In addition, a user or a manufacturer's test engineer can generate an instruction or an event for executing at least one program loaded in the RAM 212 via the user interface 220. For example, at least one program programmed in the ROM 214 can be loaded into the RAM 212 via the bus under the control of the CPU 210.

The image data processing circuit 230A includes a compensation circuit 232, a first conversion circuit 234, an adjustment circuit 236A, and a second conversion circuit 238.
The compensation circuit 232 adjusts at least one of the original RGB values based on the second control value PL_CTR, and generates first image data, for example, a first RGB value based on the result of the adjustment.
In order to prevent an overflow that occurs when the saturation value or chrominance value is increased using the adjustment circuit 236A, that is, saturation of the saturation value or the chrominance value, the compensation circuit 232 includes the original RGB value. Performs the function of adjusting the value in advance, for example, decreasing it.

However, depending on the embodiment, when the image data processing circuit 230 </ b> A does not include the compensation circuit 232, the original RGB value output from the display controller 215 may be directly input to the first conversion circuit 234.
The first conversion circuit 234 converts the original RGB value or the first RGB value into a luminance value and a saturation value (in some cases, a color difference value).
For example, the first conversion circuit 234 can convert an RGB value in the RGB color space into a YCbCr value in the YCbCr color space. At this time, Y is a luminance component, and CbCr is two chroma components. The luminance value means the Y value, and the saturation value means the CbCr value.

In this specification, for convenience of explanation, an example in which the original RGB value or the first RGB value is converted into a YCbCr value and an example in which the adjusted YCbCr value is converted back into the second RGB value are described. The technical idea is conversion between RGB values and YUV values, conversion between RGB values and Y′CbCr values, conversion between RGB values and YDbDr values, conversion between RGB values and YIQ values. Alternatively, the present invention can be directly applied to conversion between RGB values and YCoCg values.
That is, the technical idea of the present invention is to reduce the luminance value in order to reduce the power consumption in the display 300, for example, an organic light emitting diode display, and at the same time visually perceptual brightness of the image displayed on the display 300. In order to maintain the image quality, the present invention can be applied to an image data processing circuit that increases a saturation (or color difference in some cases) value.

Accordingly, the chroma components used in the present specification are understood as concepts including chrominance components, and the chroma values are understood as concepts including chrominance values. Is done.
The adjustment circuit 236A adjusts the luminance value and the saturation value based on the first control values YV_CTR and CH_CTR. The adjustment circuit 236A includes a target indicator 236-1, a luminance control circuit 236-2, and a saturation (or color difference in some cases) control circuit 236-3.
The target indicator 236-1 can be implemented as a register. The target indicator 236-1 can generate the luminance control value YV_CTR and the saturation control value CH_CTR based on the control value CTR output from the CPU 210.

  According to the embodiment, the CPU 210 may generate the control value CTR based on the setting value SV or the user input value set by the user via the user interface 220. According to another embodiment, the CPU 210 may generate the control value CTR based on the setting value SV set by a manufacturer, for example, a test engineer via the user interface 220. In this case, the user can change the setting value SV set by the test engineer via the user interface 220.

According to still another embodiment, the CPU 210 performs a type of application program (application program) executed by the user or test engineer to process the original RGB value or the first RGB value, for example, a moving image reproduction application program, a still image reproduction An application program, a game execution application program, a UI (User Interface) execution application program, a GUI (Graphic User Interface) execution application program, or the like can be determined, and a control value CTR can be generated based on the determination result.
Therefore, the target indicator 236-1 can generate the first control values YV_CTR and CH_CTR based on the control value CTR output from the CPU 210.

Based on the luminance control value YV_CTR, the luminance control circuit 236-2 can adjust, for example, decrease the luminance value output from the first conversion circuit 234. For example, the brightness control value YV_CTR may be a value corresponding to a power saving ratio indicating how much power consumption in the display 300 is reduced.
Based on the saturation control value CH_CTR, the saturation (or color difference in some cases) control circuit 236-3 adjusts the saturation value (or color difference value in some cases) output from the first conversion circuit 234, for example, Can be increased.

The second conversion circuit 238 can convert the YCbCr value in the YCbCr color space again into the RGB value in the RGB color space. For example, each of the conversion circuits 234 and 238 includes an ITU-R (International Telecommunication Union Radiocommunication Sector) BT. 601 conversion, ITU-R BT. Conversion according to 709 conversion, JPEG conversion, or digital TV broadcast standard can be performed.
The second conversion circuit 238 generates second image data, for example, a second RGB value based on the adjusted luminance value and the adjusted saturation value, and outputs the generated second RGB value to the display 300. To do.

The display 300 can display a desired image according to the second RGB values. If the perceived brightness of the image displayed on the display 300 based on the original RGB value is compared with the perceived brightness of the image displayed on the display 300 based on the second RGB value, the reduced brightness value may be used in the display 300. However, the cognitive brightness of the image displayed on the display 300 according to the increased saturation value is maintained or increased as it is.
FIG. 2 shows a block diagram of an image data display system according to another embodiment of the present invention. Referring to FIG. 2, the image data display system or image data processing system 100B includes a processor 200B, a display 300, and an external memory 400.

The processor 200B can include a CPU 210, a display controller 215, a user interface 220, and an image data processing circuit 230B.
As described above, the processor 200B may further include the RAM 212, the ROM 214, the external memory controller 216, and the GPU 218.
The image data processing circuit 230B includes a statistical analysis circuit 231, a compensation circuit 232, a first conversion circuit 234, a control value generation circuit 235, an adjustment circuit 236B, and a second conversion circuit 238.
The statistical analysis circuit 231 analyzes a histogram pattern defined as a cumulative distribution of each of the original RGB values output from the display controller 215, and generates an HPI as a control value as a result of the analysis. Output to the circuit 235.

3A to 3D show histogram patterns of image data input to the statistical analysis circuit of FIG.
Each of FIGS. 3A-3D represents a cumulative distribution for each of the original RGB values.
The X axis of each cumulative distribution table for one image processing unit, eg, one frame, represents RGB values, eg, brightness or grayscale voltage, and the Y axis of the cumulative distribution table represents frequency. (Frequency).
As shown in each of FIGS. 3A-3D, when each of the RGB values is represented as 8 bits, the brightness or grayscale voltage may have 256 levels.

FIG. 3A shows a histogram pattern containing many RGB values having intermediate levels. FIG. 3B shows a histogram pattern that includes fewer RGB values having intermediate levels. FIG. 3C shows a histogram pattern containing many RGB values having low levels. FIG. 3D shows a histogram pattern containing many RGB values with high levels. The four graphs (or four curves) shown in FIGS. 3A to 3D are exemplarily shown for convenience of explanation.
Depending on the embodiment, the statistical analysis circuit 231 analyzes a histogram pattern defined as a cumulative distribution of each of the original RGB values, and depending on the result of the analysis, the histogram pattern is converted into a plurality of histogram patterns shown in FIGS. 3A to 3D. Classification into any one of the graphs and histogram pattern information HPI corresponding to the result of the classification can be output.

The histogram pattern information HPI may be a cumulative value for each of the original RGB values, a value corresponding to the one-dimensional graph generated by the analysis result, or a value corresponding to the two-dimensional graph generated by the analysis result.
The control value generation circuit 235 can generate the first control values YV_CTR and CH_CTR and the second control value PL_CTR based on the histogram pattern information HPI.
Depending on the operation mode, the control value generation circuit 235 can generate the first control values YV_CTR, CH_CTR and the second control value PL_CTR based on the control value CTR output from the CPU 210.

Under the control of the CPU 210, the control value generation circuit 235 can generate the first control values YV_CTR, CH_CTR and the second control value PL_CTR based on the histogram pattern information HPI or the control value CTR.
That is, the CPU 210 can set whether the control value generation circuit 235 generates the first control values YV_CTR, CH_CTR and the second control value PL_CTR based on the histogram pattern information HPI or the control value CTR. This setting can be determined by the setting value SV output from the user interface 220.
As described above, based on (i) the user, (ii) the manufacturer's test engineer, (iii) the type of application program to be executed, or (iv) the histogram pattern information HPI, the first control values YV_CTR, CH_CTR and the first Two control values PL_CTR can be generated.

Based on the luminance control value YV_CTR, the luminance control circuit 236-2 can adjust, for example, decrease the luminance value output from the first conversion circuit 234. Based on the saturation control value CH_CTR, the saturation control circuit 236-3 can adjust, for example, increase the saturation value output from the first conversion circuit 234. The second conversion circuit 238 generates a second RGB value based on the adjusted luminance value and the adjusted saturation value, and outputs the generated second RGB value to the display 300. The display 300 can display a desired image according to the second RGB values.
4A to 4D show patterns for explaining the operation of the compensation circuit of FIG.

The control value generation circuit 235 outputs the second control value PL_CTR to the compensation circuit 232 in order to equalize the histogram pattern or adjust at least one of the original RGB values. For example, when the histogram pattern is the same as the graph of FIG. 3A, the control value generation circuit 235 outputs the second control value PL_CTR corresponding to the graph of FIG. 4A to the compensation circuit 232.
When the histogram pattern is the same as the graph of FIG. 3B, the control value generation circuit 235 outputs the second control value PL_CTR corresponding to the graph of FIG. 4B to the compensation circuit 232. When the histogram pattern is the same as the graph of FIG. 3C, the control value generation circuit 235 outputs the second control value PL_CTR corresponding to the graph of FIG. 4C to the compensation circuit 232.

When the histogram pattern is the same as the graph of FIG. 3D, the control value generation circuit 235 outputs the second control value PL_CTR corresponding to the graph of FIG. 4D to the compensation circuit 232.
The compensation circuit 232 adjusts at least one of the original RGB values based on the second control value PL_CTR output from the control value generation circuit 235, and the first image data, for example, A first RGB value is generated. As described above, the image data processing circuit 230B may not include the compensation circuit 232.
FIG. 5 is a conceptual diagram illustrating a method of adjusting the luminance value and the saturation value for each region. As shown in FIG. 5, the image displayed on the display 300 may include a plurality of regions 301, 302, and 303.

When the first region 301 is a background region, the second region 302 is a UI region or a GUI region, and the third region 303 is a moving image playback (playing back) region, the image data processing circuit 230A or 230B independently or exclusively adjusts the luminance value and the saturation value for each region based on position information (eg, P11 and P12 and / or P21 and P22) defining each region. can do.
The position information is obtained from a synchronization signal transmitted from the display controller 215 to the image data processing circuit 230A or 230B, for example, a vertical synchronization signal and a horizontal synchronization signal.

Each position (or position information) of the plurality of areas 301, 302, and 303 displayed on the display 300 can be changed depending on the type of application program to be executed, for example, a media player. The position information for each of the regions 301, 302, and 303 can be generated by an application program to be executed.
Therefore, each adjustment circuit 236A or 236B adjusts the luminance value and the saturation value for each region 301, 302, and 303 based on the first control values YV_CTR and CH_CTR for each region 301, 302, and 303. can do. For example, each adjustment circuit 236A or 236B can adjust the luminance value and the saturation value for the second region 302 and the luminance value and the saturation value for the third region 303 different from each other.

As described with reference to FIGS. 1 to 5, each adjustment circuit 236 </ b> A or 236 </ b> B can adjust the luminance value and the saturation value for each of the entire frame or a plurality of regions included in the entire frame. .
FIG. 6 is a flowchart illustrating an image data processing method according to an embodiment of the present invention. Referring to FIGS. 1 to 6, whether to execute the step S100 may be determined according to how the image data processing circuit 230A or 230B is implemented. That is, whether to execute step S100 is determined depending on whether the image data processing circuit 230A or 230B includes the statistical analysis circuit 231 and / or the compensation circuit 232.

As shown in FIG. 2, when the image data processing circuit 230B includes both the statistical analysis circuit 231 and the compensation circuit 232, histogram analysis is performed on the original RGB values (step S111), and the result of the analysis At least one of the original RGB values is adjusted by the second control value PL_CTR generated based on (Step S113). That is, pre-level compensation is performed.
As shown in FIG. 1, when the image data processing circuit 230A does not include the statistical analysis circuit 231, the compensation circuit 232 adjusts at least one of the original RGB values by the second control value PL_CTR. Based on the result of the adjustment, a first RGB value is generated (step S113).

When the image data processing circuits 230A and 203B do not include the statistical analysis circuit 231 and the compensation circuit 232, the original RGB values are directly input to the first conversion circuit 234.
First color conversion is performed by the first conversion circuit 234. That is, the first RGB value is converted into a Y value and a CbCr value (step S120). The adjustment circuit 236B decreases the Y value and increases the CbCr value based on the first control values YV_CTR and CH_CTR (step S130).
The second color conversion is performed by the second conversion circuit 238. That is, a second RGB value is generated using the decreased Y value and the increased CbCr value (step S140). The second RGB value, that is, the converted image data is displayed on the display 300.

As described above, as the luminance value decreases and the saturation value (in some cases, the color difference value) increases, the power consumption of the display 300 decreases and the brightness, that is, the visual cognitive brightness, increases. There is an effect to.
The processor 200A or 200B can be implemented as a system on chip (SoC). The processor 200A or 200B can be implemented as a multi-core processor.

  The present invention is used in system-on-chip, application processors, and portable electronic devices.

100A, 100B: Image data display system 200A, 200B: Processor 210: CPU
215: Display controller 216: External memory controller 218: GPU
220: User interface 230A, 230B: Image data processing circuit 231: Statistical analysis circuit 232: Compensation circuit 234: First conversion circuit 235: Control value generation circuit 236A, 236B: Adjustment circuit 236-1: Target indicator or register 236- 2: Brightness adjustment circuit 236-3: Saturation adjustment circuit 238: Second conversion circuit 300: Display 400: External memory

Claims (10)

In a system-on-chip (SoC) that can control the operation of an organic light-emitting diode (OLED) display,
A first conversion circuit for converting the first RGB value into a luminance value and a saturation value;
An adjustment circuit for adjusting the luminance value and the saturation value based on a first control value;
A second conversion circuit that generates a second RGB value based on the adjusted luminance value and the adjusted saturation value, and outputs the generated second RGB value to the OLED display;
SoC including   The SoC according to claim 1, further comprising a compensation circuit that adjusts at least one of the original RGB values based on the second control value, and generates the first RGB value according to a result of the adjustment. Registers,
A user interface for receiving user input values;
A CPU that generates the first control value and the second control value based on the user input value output from the user interface, and stores the first control value and the second control value in the register. (Central Processing Unit),
The SoC according to claim 2, further comprising: Registers,
A type of an application program executed to process the original RGB value is determined, and the first control value and the second control value are generated based on the determination result, and the first control value And a CPU for storing the second control value in the register;
The SoC according to claim 2, further comprising: The CPU
Based on the position information for each region displayed on the OLED display, the first control value for each region and the second control value for each region are generated,
The adjustment circuit exclusively adjusts the luminance value and the saturation value for each region based on the first control value for each region,
5. The compensation circuit adjusts at least one of the original RGB values for each region based on the second control value for each region, and generates the first RGB value for each region. SoC described in 1. A statistical analysis circuit that analyzes a histogram pattern defined as a cumulative distribution of each of the original RGB values and outputs a result of the analysis;
A control value generation circuit that generates the first control value and the second control value based on the result of the analysis;
The SoC according to claim 2, further comprising: In a mobile application processor capable of controlling the operation of an organic light emitting diode (OLED) display,
A first conversion circuit for converting the first RGB value into a luminance value and a saturation value;
An adjustment circuit for adjusting the luminance value and the saturation value based on a first control value;
A second conversion circuit that generates a second RGB value based on the adjusted luminance value and the adjusted saturation value, and outputs the generated second RGB value to the OLED display;
A compensation circuit that adjusts at least one of the original RGB values based on a second control value to generate the first RGB value;
A display controller that outputs the original RGB values;
Including mobile application processor. Registers,
A user interface for receiving user input values;
A CPU that generates the first control value and the second control value based on the user input value output from the user interface, and stores the first control value and the second control value in the register. When,
The mobile application processor of claim 7 further comprising: Registers,
A type of an application program executed to process the original RGB value is determined, and the first control value and the second control value are generated based on the determination result, and the first control value And a CPU for storing the second control value in the register;
The mobile application processor of claim 7 further comprising: An organic light emitting diode (OLED) display;
A first conversion circuit for converting the first RGB value into a luminance value and a saturation value;
An adjustment circuit for adjusting the luminance value and the saturation value based on a first control value;
A second conversion circuit that generates a second RGB value based on the adjusted luminance value and the adjusted saturation value, and outputs the generated second RGB value to the OLED display;
A compensation circuit that adjusts at least one of the original RGB values based on a second control value to generate the first RGB value;
A display controller that outputs the original RGB values;
Portable electronic device including

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